The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
U.S. Pat. No. 7,291,578 discloses a hybrid anion exchanger for selective removal of contaminating ligands from fluids and method of manufacture thereof. Polymeric anion exchangers are used as host materials in which hydrated Fe(III) Oxides (HFO) are irreversibly dispersed within the exchanger beads. Since the anion exchangers have positively charged quaternary ammonium functional groups, anionic ligands such as arsenates, chromates, oxalates, phosphates, phthalates can permeate in and out of the gel phase. Consequently, anion exchanger-supported HFO micro particles exhibit significantly greater capacity to remove arsenic and other ligands in comparison with cation exchanger supports. Loading of HFO particles is carried out by preliminary loading of the anion exchange resin with an oxidizing anion such as (manganate) MnO4− or hypochlorite (OCl−), followed by passage of a Ferrous Sulfate solution through the resin.
U.S. Pat. No. 9,901,918 discloses a hybrid ion exchange material and method for making the same. A high capacity hybrid ion exchange material with enhanced ability to selectively remove molecular (organics) and anionic (fluoride ion and oxyanions of phosphorus and arsenic) species from drinking water, industrial streams, and wastes, for applications predominantly in the medical and food industries. A hybrid ion exchange material comprising: an activated carbon carrier; precipitated mixed oxide including alumina; doping polyvalent metal oxide including titanium, zirconium, tin, cerium, lanthanum, iron, or manganese, or any combination thereof; and, wherein said mixed oxide or said doping polyvalent metal oxide or both are configured to selectively adsorb organic molecules, fluoride ion, or oxyanions of phosphorus and arsenic.
U.S. Pat. No. 9,120,093 discloses a hybrid anion exchanger impregnated with hydrated zirconium oxide for selective removal of contaminating ligand and methods of manufacture and use thereof. Polymeric anion exchanger are used as host materials in which sub-micron sized hydrated Zr(IV) oxides (HZrO) particles are irreversibly dispersed within the ion exchange medium, such as beads or fibers. The hydrated Zirconium oxide can be impregnated into the pore structure of resin by mixing the parent anion exchange resin with zirconium solution prepared by pre-calcined zirconium oxide dissolved in concentrated mixture of alcohol and acid, and then followed by precipitation of HZrO particles within the resin by using alkaline solution. Since the anion exchangers have positively charged such as quaternary ammonium functional groups, anionic ligands such as arsenate, fluoride can transport in and out of the gel phase. Consequently, anion exchanger-supported HZrO submicron particles exhibit significantly greater capacity to remove arsenic and fluoride in comparison with parent anion exchange.
U.S. Pat. No. 9,663,389 discloses the use of MgO doped with a divalent or trivalent metal cation for removing arsenic from water. Systems and methods for use of magnesium hydroxide, either directly or through one or more precursors, doped with a divalent or trivalent metal cation, for removing arsenic from drinking water, including water distribution systems. In one embodiment, magnesium hydroxide, Mg(OH)2 (a strong adsorbent for arsenic) doped with a divalent or trivalent metal cation is used to adsorb arsenic. The complex consisting of arsenic adsorbed on Mg(OH)2 doped with a divalent or trivalent metal cation is subsequently removed from the water by conventional means, including filtration, settling, skimming, vortexing, centrifugation, magnetic separation, or other well-known separation systems. In another embodiment, magnesium oxide, MgO, is employed, which reacts with water to form Mg(OH)2. The resulting Mg(OH)2 doped with a divalent or trivalent metal cation, then adsorbs arsenic, as set forth above. The method can also be used to treat human or animal poisoning with arsenic.
U.S. Pat. No. 7,341,667 discloses a process for reduction of inorganic contaminants from waste streams: The invention relates to the use of used alumina to reduce the level of inorganic contaminants, such as mercury and arsenic, from waste fluid streams. The invention further provides a process for reducing the level of mercury or arsenic in fluid streams by contacting the fluid stream with used alumina, such as used Claus catalyst. However, there is still need for a water purification composition that removes phosphorus and other contaminants from contaminated waters.
U.S. Pat. No. 9,095,837 discloses a method for the production and use of a metal oxide-containing resin present in a quaternary amine (“quat”) modified substrate, such as wood and other hydroxyl and amino groups present on the surface of the substrate. The method requires treating a substrate material having a functional group with a quaternary amine compound to form a function site. Specifically, the method requires the modification of the substrate using an epoxy form of 3-chloro-2-hydroxypropyltrimethylammonium chloride prior to deposition of metal oxide on the quat-modified substrate. The modification requires use of the toxic epoxy component or generation of the epoxy reactant through use of a strong base (such as sodium hydroxide) on 3-chloro-2-hydroxypropyltrimethylammonium chloride. This could be dangerous for the technicians working around this material who could be subject to sensitization upon inhalation or contact with the material. The strong caustic material used can also cause chemical burns and attack the eyes upon contact. The odor and toxicity associated with volatilization of the quat is also of concern to workers involved in the production of the media.
Therefore, there is still need for a water purification composition that removes phosphorus and other contaminants from contaminated waters, which is cheap, effective, versatile, benign, reusable and capable of being made from a renewable resource that can compete and replace existing commercial composition in the water purification arena. The composition should exhibit fast kinetics (removal rate) and have a high capacity in terms of the amount of phosphorus removed per given mass of the active and expensive ingredient in the composition. No composition currently exists that satisfies all the above properties. Several commercial composition exist that exhibit one or more of the desirable properties named above, but the search for an extremely versatile composition that supersedes the existing varieties of products has alluded researchers so far.